Field of the Invention
The invention relates to a device for holding and tautening cylinder packings on printing machine cylinders, with at least one tension element whereon a cylinder packing is held, the tension element being pivotable coaxially with the cylinder axis, the device of the invention, in particular, clamping metal foils on transfer cylinders of sheet-fed rotary offset printing machines; and a printing machine including the device.
German Patent 33 00 678 discloses a device for holding and tautening or clamping a wrap-round plate on a cylinder for rotogravure or intaglio printing presses, wherein the cylinder packing is tautened or clamped by coaxially pivoting a tension member about the axis of a gravure cylinder. The tension member is driven by a clamping element which is supported between a pivotable and a stationary portion of the cylinder. Due to the arrangement of the clamping element, the pivot angle or angle of traverse of the clamping element in the described tautening or clamping device is greatly restricted, so that edge battens or strips capable of being pivoted out of the outer contour of the cylinder are necessary in order to suspend the end of the cylinder packing.
German Patent 609 099 describes a fastening and tautening or clamping device for flexible printing plates, which has a lever device made up of a double rod or link arranged outside the cylinder and adjustable by a worm gear, and a pivotable batten or strip fastened to a lever arm. Although, with such a clamping device, it is possible to fix the rotary position of the pivoted clamping element in various positions and does not require a component projecting out of the outer contour of the cylinder, the handling and operation of the described clamping device is complicated and laborious, particularly on a cylinder which is installed in the printing machine and to which access is made difficult by adjacent assemblies. The described device does not disclose any means for permitting a rapid pivoting of the clamping element through a larger pivot angle for the purpose of affording favorable access when the cylinder packing is being fastened. There is also no disclosure therein of any springs which ensure that the device has a constant and reproducible tensioning or tautening effect and, in the event of material fatigue and in the case of dimensional deviations of the cylinder packing, have a compensating effect.